包钢U71Mn钢轨Mn含量优化研究

Study on Optimizing Mn Content of U71Mn Rail of Baotou Steel

为改善产品质量,加强高速钢轨质量监控,对U71Mn钢轨化学成分进行优化,降低钢中Mn含量,同时控制轧制工艺,在U71Mn 60N、60 kg/m、50 kg/m、QU120、QU100、QU80等全系列断面进行试制。结果表明:Mn含量优化后U71Mn钢轨性能与优化前U71Mn钢轨比较,U71Mn钢轨抗拉强度较优化前降低7.2 MPa,均值达到950 MPa,踏面硬度降低2.8,均值达到269.2,延伸率基本不变,获得理想的珠光体组织,钢轨性能均能满足标准要求,并且具有足够富余量,取得了较好的效果。

In order to improve product quality and strengthen quality monitoring of high speed rail, the chemical composition of U71Mn rail is optimized, Mn content in steel is reduced and rolling process is controlled as well as the trial productions are carried out for such whole series of sections as 60 N, 60 kg/m, 50 kg/m, QU120, QU100 and QU80 of U71Mn. The results showed that the tensile strength was reduced by 7.2 MPa and mean value reached 950 MPa, tread hardness(HB) was reduced by 2.8 and mean value reached 269.2 as well as elongation is basically unchanged by comparing the performances of U71Mn rail with those before optimization. Moreover, the ideal perlite structure is obtained, performances of rail could all meet the standard requirements and is with enough margin so that the effects are better.